Two mothers who lost sons to gun violence joined ministers and an activist Tuesday in a lawsuit against three Chicago suburbs, alleging that weak oversight of gun shops has allowed criminals to easily obtain weapons flowing into a city besieged by gun violence.

The lawsuit accuses Lyons, Riverdale and Lincolnwood communities of violating the civil rights of residents in Chicago’s largely African American neighborhoods by failing to take concrete steps to make sure gun stores are not selling weapons to people who shouldn’t be allowed to carry them.